Hydroxypropyl methylcellulose HPMC ndi mtundu wa non-ionic cellulose wosakanizidwa ether.Mosiyana ndi ionic methyl carboxymethyl cellulose ether yosakanikirana, sichimakhudzana ndi zitsulo zolemera.Chifukwa cha kusiyanasiyana kwa methoxyl ndi hydroxypropyl zomwe zili mu hydroxypropyl methylcellulose ndi ma viscosities osiyanasiyana, pali mitundu yambiri yokhala ndi zinthu zosiyanasiyana, mwachitsanzo, kuchuluka kwa methoxyl komanso kutsika kwa hydroxypropyl Kuchita kwake kumayandikira kwa methyl cellulose, pomwe kutsika. Zomwe zili ndi methoxyl komanso kuchuluka kwa hydroxypropyl zili pafupi ndi za hydroxypropyl methyl cellulose.Komabe, muzosiyanasiyana, ngakhale kuti pali gulu laling'ono chabe la hydroxypropyl kapena gulu laling'ono la methoxyl, pali kusiyana kwakukulu kwa kusungunuka kwa zosungunulira za organic kapena kutentha kwa flocculation mu njira zamadzimadzi.
(1) Kusungunuka kwa hydroxypropyl methylcellulose
①Kusungunuka kwa hydroxypropyl methylcellulose m'madzi Hydroxypropyl methylcellulose kwenikweni ndi mtundu wa methylcellulose wosinthidwa ndi propylene oxide (methoxypropylene), kotero imakhalabe ndi zinthu zomwezo monga methyl cellulose Cellulose ili ndi mawonekedwe ofanana ndi kusungunuka kwamadzi ozizira komanso kusasungunuka kwamadzi otentha.Komabe, chifukwa cha gulu losinthidwa la hydroxypropyl, kutentha kwake kwa gelation m'madzi otentha ndikokwera kwambiri kuposa methyl cellulose.Mwachitsanzo, kukhuthala kwa hydroxypropyl methylcellulose yankho lamadzi lamadzi ndi 2% methoxy content substitution degree DS=0.73 ndi hydroxypropyl content MS=0.46 ndi 500 mpa·s pa 20°C, ndi kutentha kwake kwa gel Imatha kufika pafupifupi 100°C, pomwe methyl cellulose pa kutentha komweko ndi pafupifupi 55 ° C.Ponena za kusungunuka kwake m'madzi, zasinthidwanso kwambiri.Mwachitsanzo, pulverized hydroxypropyl methylcellulose (granular shape 0.2 ~ 0.5mm pa 20°C ndi 4% amadzimadzi kukhuthala 2pa•s akhoza kugulidwa Pa kutentha firiji, mosavuta sungunuka m'madzi popanda kuzirala.
②Kusungunuka kwa hydroxypropyl methylcellulose mu organic solvents Kusungunuka kwa hydroxypropyl methylcellulose mu zosungunulira za organic kulinso bwino kuposa methylcellulose.Zogulitsa pamwamba pa 2.1, high-viscosity hydroxypropyl methylcellulose munali hydroxypropyl MS = 1.5 ~ 1.8 ndi methoxy DS=0.2 ~ 1.0, ndi okwana digiri ya m'malo pamwamba 1.8, ndi sungunuka mu anhydrous methanol ndi Mowa njira Medium, ndi madzi-soluble. .Imasungunukanso mu ma hydrocarboni a chlorine monga methylene chloride ndi chloroform, ndi zosungunulira organic monga acetone, isopropanol ndi diacetone mowa.Kusungunuka kwake mu zosungunulira za organic ndikwabwino kuposa kusungunuka kwamadzi.
(2) Zomwe zimakhudza kukhuthala kwa hydroxypropyl methylcellulose Kutsimikiza kwa kukhuthala kwa hydroxypropyl methylcellulose ndikofanana ndi ma cellulose ethers, ndipo amayezedwa pa 20 ° C ndi 2% yankho lamadzi monga muyezo.Kukhuthala kwa mankhwala omwewo kumawonjezeka ndi kuwonjezeka kwa ndende.Kwa mankhwala omwe ali ndi zolemera zosiyana za maselo pamagulu omwewo, mankhwala omwe ali ndi kulemera kwakukulu kwa maselo amakhala ndi kukhuthala kwakukulu.Ubale wake ndi kutentha ndi wofanana ndi wa methyl cellulose.Kutentha kukakwera, kukhuthala kumayamba kuchepa, koma ikafika kutentha kwina,
kukhuthala kumatuluka mwadzidzidzi ndipo gelation imachitika.Kutentha kwa gel otsika-kukhuthala kwakanthawi ndikokwera kwambiri.ndi mkulu.Mfundo yake ya gel sikuti imangokhudzana ndi kukhuthala kwa ether, komanso yokhudzana ndi kuchuluka kwa gulu la methoxyl ndi gulu la hydroxypropyl mu ether komanso kukula kwa digiri yonse yolowa m'malo.Tiyenera kuzindikira kuti hydroxypropyl methylcellulose imakhalanso pseudoplastic, ndipo yankho lake ndi lokhazikika kutentha kwa firiji popanda kuwonongeka kulikonse mu mamasukidwe akayendedwe kupatula kuthekera kwa kuwonongeka kwa enzymatic.
(3) Kulekerera kwa mchere wa hydroxypropyl methylcellulose Popeza hydroxypropyl methylcellulose ndi ether yosakhala ya ionic, siipanga ioni m'madzi, mosiyana ndi ma ionic cellulose ethers, Mwachitsanzo, carboxymethyl cellulose imakhudzidwa ndi ayoni achitsulo cholemera ndipo imatuluka mu yankho.Mchere wambiri monga chloride, bromide, phosphate, nitrate, ndi zina zotero.Komabe, kuwonjezera mchere ali ndi chikoka pa flocculation kutentha ake amadzimadzi njira.Pamene ndende mchere ukuwonjezeka, kutentha gel osakaniza amachepetsa.Pamene mchere ndende ndi pansi pa flocculation mfundo, ndi mamasukidwe akayendedwe a yankho amakonda kuwonjezeka.Choncho, mchere wambiri umawonjezeredwa., mu ntchito, akhoza kukwaniritsa thickening zotsatira kwambiri chuma.Choncho, mu ntchito zina, ndi bwino kugwiritsa ntchito chisakanizo cha cellulose ether ndi mchere kusiyana ndi njira yowonjezera ya ether kuti ikwaniritse thickening kwenikweni.
(4) Hydroxypropyl methylcellulose acid ndi alkali resistance Hydroxypropyl methylcellulose nthawi zambiri imakhala yokhazikika ku ma acid ndi alkalis, ndipo sichikhudzidwa ndi pH 2 ~ 12.Zitha kupirira kuchuluka kwa Kuwala zidulo, monga asidi formic, asidi asidi, citric asidi, succinic asidi, asidi phosphoric, asidi boric, etc. Koma ndende asidi ali ndi zotsatira za kuchepetsa mamasukidwe akayendedwe.Alkalis monga caustic soda, caustic potashi ndi madzi a mandimu alibe mphamvu pa izo, koma amatha kuonjezera kukhuthala kwa yankho, ndiyeno pang'onopang'ono kuchepetsa.
(5) Miscibility ya hydroxypropyl methylcellulose Hydroxypropyl methylcellulose yankho akhoza kusakaniza ndi madzi sungunuka polima mankhwala kukhala yunifolomu ndi mandala njira ndi apamwamba mamasukidwe akayendedwe.Ma polima awa amaphatikiza polyethylene glycol, polyvinyl acetate, polysilicone, polymethylvinylsiloxane, hydroxyethyl cellulose, ndi methyl cellulose.Zosakaniza zachilengedwe monga chingamu cha arabic, dzombe chingamu, chingamu cha karaya, ndi zina zotero, zimagwirizananso bwino ndi yankho lake.Hydroxypropyl methylcellulose imathanso kusakanizidwa ndi mannitol ester kapena sorbitol ester ya stearic acid kapena palmitic acid, komanso imatha kusakanikirana ndi glycerin, sorbitol ndi mannitol, ndipo mankhwalawa angagwiritsidwe ntchito ngati hydroxypropyl methylcellulose Plasticizer ya cellulose.
(6) Ma cellulose ether osasungunuka m'madzi a hydroxypropyl methylcellulose amatha kulumikizidwa ndi ma aldehydes pamtunda, kotero kuti ma ether osungunuka m'madziwa amalowetsedwa mu yankho ndikukhala osasungunuka m'madzi.Ma aldehydes omwe amapanga hydroxypropyl methylcellulose osasungunuka amaphatikizapo formaldehyde, glyoxal, succinic aldehyde, adipaldehyde, ndi zina. Mukamagwiritsa ntchito formaldehyde, chidwi chapadera chiyenera kuperekedwa ku pH ya yankho, yomwe glyoxal imachita mofulumira, kotero glyoxal amagwiritsidwa ntchito ngati crosslinking. wothandizira pakupanga mafakitale.Kuchuluka kwa mtundu woterewu wolumikizana nawo mu yankho ndi 0,2% ~ 10% ya unyinji wa ether, makamaka 7% ~ 10%, mwachitsanzo, 3.3% ~ 6% ya glyoxal ndi yoyenera kwambiri.Nthawi zambiri, mankhwala
kutentha ndi 0 ~ 30 ℃, ndipo nthawi ndi 1 ~ 120min.Kuphatikizika kolumikizana kuyenera kuchitika pansi pa acidic.Nthawi zambiri, yankho limayamba kuwonjezeredwa ndi asidi amphamvu kapena organic carboxylic acid kuti musinthe pH ya yankho kukhala pafupifupi 2 ~ 6, makamaka pakati pa 4 ~ 6, kenako ndikuwonjezera ma aldehydes kuti achite zomwe zimalumikizana.Zomwe zimagwiritsidwa ntchito zimakhala ndi hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid kapena citric acid etc., momwemo ndi formic acid kapena acetic acid ndizoyenera, ndipo formic acid ndi yabwino.Asidi ndi aldehyde amathanso kuwonjezeredwa nthawi imodzi kuti alole yankho kuti ligwirizane ndi njira yolumikizirana pakati pa pH yomwe mukufuna.Izi nthawi zambiri amagwiritsidwa ntchito pomaliza chithandizo pokonzekera ma cellulose ethers.Pambuyo pa cellulose ether ndi yosasungunuka, ndizosavuta kugwiritsa ntchito
20 ~ 25 ℃ madzi ochapira ndi kuyeretsa.Mankhwalawa akagwiritsidwa ntchito, zinthu zamchere zimatha kuwonjezeredwa ku yankho la mankhwalawa kuti zisinthe pH ya yankho kuti ikhale yamchere, ndipo mankhwalawa amasungunuka mwachangu.Njirayi imagwiranso ntchito pochiza filimuyo pambuyo poti njira ya cellulose ether imapangidwira filimu kuti ikhale filimu yosasungunuka.
(7) The enzyme kukana kwa hydroxypropyl methylcellulose ndi theoretically cellulose zotumphukira, monga gulu lililonse anhydroglucose, ngati pali zolimba omangika wolowa gulu, si kophweka kuti kachilombo ndi tizilombo, koma kwenikweni yomalizidwa mankhwala Pamene mtengo m'malo kuposa. 1, idzasokonezedwanso ndi michere, zomwe zikutanthauza kuti kuchuluka kwa m'malo mwa gulu lililonse pa unyolo wa cellulose sikuli yunifolomu mokwanira, ndipo tizilombo tating'onoting'ono tating'onoting'ono titha kuwononga gulu la anhydroglucose losalowa m'malo kuti lipange shuga, monga zakudya zopatsa tizilombo toyambitsa matenda.Chifukwa chake, ngati kuchuluka kwa etherification m'malo mwa cellulose kumawonjezeka, kukana kwa enzymatic kukokoloka kwa cellulose ether kudzawonjezekanso.Malinga ndi malipoti, poyang'aniridwa, zotsatira za hydrolysis za michere, kukhuthala kotsalira kwa hydroxypropyl methylcellulose (DS = 1.9) ndi 13.2%, methylcellulose (DS = 1.83) ndi 7.3%, methylcellulose (DS = 1.66) ndi 3.8%, ndi hydroxyethyl cellulose ndi 1.7%.Zitha kuwoneka kuti hydroxypropyl methylcellulose ili ndi mphamvu yotsutsa ma enzyme.Choncho, kukana bwino kwa enzyme ya hydroxypropyl methylcellulose, kuphatikizapo dispersibility yake yabwino, thickening ndi kupanga mafilimu, amagwiritsidwa ntchito mu zokutira za emulsion zamadzi, ndi zina zotero, ndipo nthawi zambiri sizifunikira kuwonjezera zotetezera.Komabe, kusungirako kwa nthawi yaitali yankho kapena kuipitsidwa kotheka kuchokera kunja, zosungirako zingathe kuwonjezeredwa ngati njira yodzitetezera, ndipo chisankho chikhoza kutsimikiziridwa malinga ndi zofunikira zomaliza za yankho.Phenylmercuric acetate ndi manganese fluorosilicate ndi zoteteza zogwira mtima, koma zonse zili ndi Toxicity, chidwi chiyenera kuperekedwa ku opaleshoniyo.Kawirikawiri, 1 ~ 5mg ya phenylmercury acetate ikhoza kuwonjezeredwa ku yankho pa lita imodzi ya mlingo.
(8) Kachitidwe ka filimu ya hydroxypropyl methylcellulose Hydroxypropyl methylcellulose ili ndi zinthu zabwino kwambiri zopangira mafilimu.Njira yake yamadzimadzi kapena organic solvent solution imakutidwa pa mbale yagalasi, ndipo imakhala yopanda mtundu komanso yowonekera pambuyo poyanika.Ndipo filimu yovuta.Ili ndi kukana kwabwino kwa chinyezi ndipo imakhalabe yolimba pa kutentha kwakukulu.Ngati pulasitiki wa hygroscopic wawonjezedwa, kutalika kwake ndi kusinthasintha kwake kumatha kukulitsidwa.Pankhani yosintha kusinthasintha, mapulasitiki opangira zinthu monga glycerin ndi sorbitol ndi omwe ali oyenera kwambiri.Nthawi zambiri, ndende yothetsera vutoli ndi 2% ~ 3%, ndipo kuchuluka kwa plasticizer ndi 10% ~ 20% ya cellulose ether.Ngati zomwe zili mu plasticizer ndizokwera kwambiri, kutsika kwa colloidal dehydration kudzachitika pa chinyezi chambiri.Mphamvu yamakokedwe ya filimuyo ndi
plasticizer yowonjezeredwa ndi yayikulu kwambiri kuposa yopanda pulasitiki, ndipo imakula ndikuwonjezeka kwa kuchuluka komweko.Ponena za hygroscopicity ya filimuyi, imawonjezekanso ndi kuwonjezeka kwa kuchuluka kwa plasticizer.
Nthawi yotumiza: Nov-24-2022